Ionizing radiation, industrial applications

It is clear that, along with the discovery of x-rays in 1895, Roentgen also found the chemical action of ionizing radiation. He drew attention to the similarity of the photographic effect induced by light and x-rays. Application to medicine appeared very quickly, followed by industrial applications. However, this field of investigation remained nameless until Milton Burton, in 1942, christened it radiation chemistry to separate it from radiochemistry which is the study of radioactive nuclei. Historical and classical work in radiation chemistry has been reviewed by Mozumder elsewhere [1]. Here we will only make a few brief remarks. 

Industrial applications of ionizing radiation encompass a wide range of absorbed doses (about six orders of magnitude), dose rates (about twelve orders of magnitude), and energies (over two orders of magnitude). ... 

The chemistry of heterogeneous systems is far from restricted to nuclear technological applications. In heterogeneous catalysis, corrosion science, surface polymerization, biochemistry and many industrial applications such as liquid-liquid extraction, interfacial processes are of vital importance. In nuclear technological applications, the presence of ionizing radiation increases the complexity further. 

The possibility of initiating chemical reactions by means of the ionizing radiation from radionuclides has been extensively investigated, but it has not found the broad application in industry that had been expected, because of possible radiation hazards. 

Fifty years of research and development works in polymer radiation Chemistry has led to a number of commercial applications as mentioned very briefly in the Introduction section. Application of ionizing radiation to polymeric materials still remains to be a very active area and the polymer and plastics industry is constantly benefiting from the innovations and fruitful results obtained from the R D works of researchers from all over the world. In the remaining part of this report a modest effort will be made to provide a survey of current developments in applied radiation chemistry of polymers and emerging new applications. 

Polymers which undergo radiation degradation on exposure to radiation are also important commercially. The best-known example is the group of polymers used as positive resist materials in electron beam microlithography. These include aliphatic poly(sulfone)s and poly(methacrylate)s. Finally, an understanding of the radiation chemistry of polymers is essential for their application in environments where they are exposed to high doses of ionizing radiation, for example in the nuclear and space industries. 

Ion-track technology based on the irradiation of thin films of various materials with accelerated heavy ions is one example of industrial application of ionizing radiation (Waheed et al. 2009). Modern heavy ion accelerators employed for irradiation of materials on the industrial scale provide beams in the 10-100 MeV/u energy range, which expands the treatment depth of considered films up to millimeters (Apel 2003). 

This industrial technology includes crosslinking of polymeric materials with the aid of ultraviolet light, ionizing radiation, or electron beams. All three processes are used industrially in many applications. 

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